Built-up panel



Patented Apr. 7, 1925.

UNITED STATES 1,532,874 PATENT OFFICE.

HARRY W. BROADY, 0F BAYSIDE, NEW YORK, ASSIG'NOR7 BY MESNE ASSIGNMENTS, TO AMERICAN BALSA WOOD CORPORATION, A CORPORATION OF NEW YORK.

BUILT-UP PANEL.

Application led June 14, 1921. Serial No. 477,475.

To all "whom it may concern:

Be it known that I, HARRY W. BROADY, a citizen of the United States, and a resident of Bayside, borough of Queens, county of Queens, and State of New York, have invented certain new and useful Improvements in Built-Up Panels, of which the following is a specification. v

This invention relates to improvements in built-up wooden panels coated with plastic material and methods of building same.

One of the objects of this invention is the provision in a coatedv wooden panel of a keying groove for the plastic material formed of a plurality of communicating groove sections whereby the contraction and expansion of the material in dry and wet conditions respectively will be compensated for by the opening and closing'of the split between the groove sections, thus eliminating splitting of the material.

Another object is the provision in such a coated wooden panel of a dovetail keying groove for theplastic material which is composed of two communicating groove-sections formed in abutting corners of any two fastened or connected strips which form a portion or the whole'of the base-board of the coated panel.

Another object of my invention is to improve the method of making such surface grooves by forming in the abutting corners of the wooden strips comprising the` base ofthe coated panel the opposite sections of the surface groove simultaneously with the formation of the dovetail tongues and grooves on and in abuttingedges of such strips or boards forming the panel, whereby the assembling and fastening together of the dovetail tongued and grooved edges will form the surface keying or d ovetail oove tor the plastic coatwith substantially no additional expense for the grooving of the surface, and the plastic coat -may thereafter be applied and keyed by these grooves to produce the built-up coatedv panel. l

With these and other objects in view, the

vinvention comprises the combination of members and arrangement of parts so combined as to co-act and cooperate with each other in the performance of the functions and the accomplishment of the results hereim contemplated, and comprises in one of its .adaptations the species or preferred cement applied at opposite sides.

This invention is applicable to the formation of surface keying grooves for coats v.of plastic material in built-up insulation panels composed of boards or strips of balsa wood or similar lightwood having substantially the characteristics of balsa wood and will be described in relation to such composite panels', though it may be utilized with other wood or similar base material.

Referring now to the accompanying drawings, 1` indicates a `portion of a panel of balsa wood which is built up of strips or boards 2v which are fastened together edgewise, and by my invention, I form a surface keying groove 3 tor the plastic coat 11 `inY the completed panel by provi-ding at the corners between the surface 6of the panel 1 and the abutting edges 4 and 5 of the strips 2 which go to make up the panel, groove sections 7 and 8 respectively, so that when two` strips 2 are `assembled and fastened together with their edges abutting, the two parts of the groove on opposite sides of the joint will communicate and form the completed groove 3 in the said surface 6 of the panel.

The strips 2 of which the panel is formed Yare preferably provided,as shown, on the opposite abutting edges with intermeshing dovetail grooves) and projections l0.- The making of such interconnectable dovetail grooves 9 and projections 10 is now accomplished with great accuracy in one operation on a suitable machine and in order to carry eut my invention, it is only necessary yto add tothe cutting tools ct such machine additional cutters or cutting portions for the formation of the two sections or portions 7 and 8 of the surface grooves 3, whereupon he surface groove portions may be termed simultaneously with the intermeshable projections and grooves. When the edges containing the intermeshable dove'a tail grooves v9 and projections 10 are slid relatively to each other to interlock or fasten the panel sections, boards or strips together, the opposite parts of the surface dovetail grooves 3 will intercommunicate at each joint to form the said completed surface dovetail groove 3.

The plastic coat 11, preferably'composed of cement orv plaster, is thereafter applied and keyed to the surface by such surface dovetail groove'or grooves 3.

The interlocking grooves 9 and projections 10 may, if desired, be slightly tapered relativelyY so that when the saine are slid relatively to each other for interconnection or interlocking, the tapered parts will cause a frictional gripping or drivin fit whlch will result in a very close and ast connection orjoint between the opposing boards, strips or sections of the base and the formation of this connection or joint will, as aforesaid, 4simultaneously produce' the dovetail surface groove 3 for keying to the surface of the panel at one or both sides thereof a layer or layers 4 of plastic material, such as cement or plaster.

Any suitable adhesive may be applied to the abutting edges of the joints between the boards or strips 6 if desired to further fasten the same together. j

It will be evident that by the use of my invention al panel composed of a built-up base may be formed with -much less expense than would be possible to produce such a panel if the surface of the panel was grooved separately from the formation of the joints between the strips, boards or sections forniing such panel base.

Having described my invention, I claim l. A composite panel comprising a base built up of a plurality of sections abutting each other edgewise and fastened together, some of such abutting sections having in each of the adjacent corners between an outer surface andthe abutting edges, a substantially half section of a surface keying groove, whereby the assembling and fastenving together of two abutting panel sections will form a complete surface keying groove, and a plastic coat ap lied on the surface of the panel and keye within such surface keying grooves. j

2.. A composite panel comprising a base built up of a plurality of wood sections abutting each other edgewise and fastened togeth'er, some of such abutting sections having 1n each of the adjacent corners between an outer surface and the abutting edges, a

substantially half section of surface keying grooves dovetail in conformation, whereby the vassembling and fasteningktogether of two abutting panel `sections will forma complete surface dovetail coat applied on the sur ace of the panel and keyed within such surface dovetailgroove.'V

3. A composite panel'co'mprising a base built up of`a -plurality of sections abutting each other edgewise and fastened together, some of such abutting sections having in the corners between an outer surface and the abutting edges, sections of surface keying grooves and also having formed within the abutting edges keying projections and grooves for interlocking the said abutting.

edges, whereby the assembling and fastengroove and a plastic ing together of two-abutting panel sections s will forma complete surface keying groove, A

edges keying yprojections and grooves for interlocking the said abutting edges, whereby the assembling and fastening together of two abutting panel sections will form a complete surface dovetail groove, and a plastic coat applied on the surface of the panel and keyed within such surface dovetail groove.

5. A composite insulation panelbuilt up of a series of strips of balsa wood abutting each other edgewise and fastened together, some of such abutting sections having in each of the adjacent corners between an outer surface and the abutting edges, a substantially half .section of a surface keying groove, dovetail in conformation, whereby the assembling and fastening together of two abutting panel-sections will form a complete surface dovetail-groove and a plastic coatlapplied on the surface of the panel and keyed within such surface dovetail groove.

In witness whereof, I'have signed my naine to the foregoing specification in the presence of two subscribing witnesses.

HARRYW., BROADY. 

